File: w32-reg.c

package info (click to toggle)
libgpg-error 1.35-1~bpo9+1
  • links: PTS, VCS
  • area: main
  • in suites: stretch-backports
  • size: 5,848 kB
  • sloc: ansic: 22,324; sh: 13,156; makefile: 488; awk: 333; lisp: 138; sed: 16
file content (154 lines) | stat: -rw-r--r-- 4,600 bytes parent folder | download | duplicates (10)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/* w32-reg.c - Windows registry support
 * Copyright (C) 2002, 2005, 2010, 2012, 2017 g10 Code GmbH
 *
 * This file is part of Libgpg-error.
 *
 * Libgpg-error is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * Libgpg-error is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, see <https://www.gnu.org/licenses/>.
 * SPDX-License-Identifier: LGPL-2.1+
 */

#if HAVE_CONFIG_H
#include <config.h>
#endif

#ifndef HAVE_W32_SYSTEM
# error This module may only be build for Windows.
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <gpg-error.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

#include "gpgrt-int.h"


/* Return a string from the W32 Registry or NULL in case of error.
 * Caller must release the return value.  A NULL for root is an alias
 * for HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE in turn.  The returned
 * string is UTF-8 encoded; ROOT, DIR, and NAME must be plain
 * ASCII. */
char *
_gpgrt_w32_reg_query_string (const char *root, const char *dir,
                             const char *name)
{
  HKEY root_key, key_handle;
  DWORD n1, nbytes, type;
  char *result = NULL;

  if (!root)
    root_key = HKEY_CURRENT_USER;
  else if (!strcmp( root, "HKEY_CLASSES_ROOT"))
    root_key = HKEY_CLASSES_ROOT;
  else if (!strcmp( root, "HKEY_CURRENT_USER"))
    root_key = HKEY_CURRENT_USER;
  else if (!strcmp( root, "HKEY_LOCAL_MACHINE"))
    root_key = HKEY_LOCAL_MACHINE;
  else if (!strcmp( root, "HKEY_USERS"))
    root_key = HKEY_USERS;
  else if (!strcmp( root, "HKEY_PERFORMANCE_DATA"))
    root_key = HKEY_PERFORMANCE_DATA;
  else if (!strcmp( root, "HKEY_CURRENT_CONFIG"))
    root_key = HKEY_CURRENT_CONFIG;
  else
    return NULL;

  if (RegOpenKeyExA (root_key, dir, 0, KEY_READ, &key_handle))
    {
      if (root)
        return NULL; /* No need for a RegClose, so return direct.  */
      /* It seems to be common practise to fall back to HKLM. */
      if (RegOpenKeyExA (HKEY_LOCAL_MACHINE, dir, 0, KEY_READ, &key_handle))
        return NULL; /* still no need for a RegClose, so return direct */
    }


  /* FIXME:  Use wide functions and convert to utf-8.  */
  nbytes = 1;
  if (RegQueryValueExA (key_handle, name, 0, NULL, NULL, &nbytes))
    {
      if (root)
        goto leave;
      /* Try to fallback to HKLM also for a missing value.  */
      RegCloseKey (key_handle);
      if (RegOpenKeyExA (HKEY_LOCAL_MACHINE, dir, 0, KEY_READ, &key_handle))
        return NULL; /* Nope.  */
      if (RegQueryValueExA (key_handle, name, 0, NULL, NULL, &nbytes))
        goto leave;
    }
  n1 = nbytes + 1;
  result = xtrymalloc (n1);
  if (!result)
    goto leave;
  if (RegQueryValueExA (key_handle, name, 0, &type, (LPBYTE) result, &n1))
    {
      xfree (result);
      result = NULL;
      goto leave;
    }
  result[nbytes] = 0; /* Make sure it is really a string.  */

#ifndef HAVE_W32CE_SYSTEM /* (Windows CE has no environment.)  */
  if (type == REG_EXPAND_SZ && strchr (result, '%'))
    {
      char *tmp;

      n1 += 1000;
      tmp = xtrymalloc (n1 + 1);
      if (!tmp)
        goto leave;
      nbytes = ExpandEnvironmentStrings (result, tmp, n1);
      if (nbytes && nbytes > n1)
        {
          xfree (tmp);
          n1 = nbytes;
          tmp = xtrymalloc (n1 + 1);
          if (!tmp)
            goto leave;
          nbytes = ExpandEnvironmentStrings (result, tmp, n1);
          if (nbytes && nbytes > n1) {
            xfree (tmp); /* Oops - truncated, better don't expand at all. */
            goto leave;
          }
          tmp[nbytes] = 0;
          xfree (result);
          result = tmp;
        }
      else if (nbytes)  /* Okay, reduce the length. */
        {
          tmp[nbytes] = 0;
          xfree (result);
          result = xtrymalloc (strlen (tmp)+1);
          if (!result)
            result = tmp;
          else
            {
              strcpy (result, tmp);
              xfree (tmp);
            }
        }
      else  /* Error - don't expand. */
        {
          xfree (tmp);
        }
    }
#endif

 leave:
  RegCloseKey (key_handle);
  return result;
}